Condensed Matter
This series consists of talks in the area of Condensed Matter.
Seminar Series Events/Videos
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Wednesday Feb 20, 2013Speaker(s):
We construct in the K matrix formalism concrete examples
of symmetry enriched topological phases, namely intrinsically topological
phases with global symmetries. We focus on the Abelian and non-chiral
topological phases and demonstrate by our examples how the interplay between
the global symmetry and the fusion algebra of the anyons of a topologically
ordered system determines the existence of gapless edge modes protected by the
symmetry and that a (quasi)-group structure can be defined among these phases.Collection/Series:Scientific Areas:
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Tuesday Feb 12, 2013Speaker(s):
The density matrix renormalization group (DMRG), which
has proved so successful in one dimension, has been making the push into higher
dimensions, with the fractional quantum Hall (FQH) effect an important target.
I'll briefly explain how the infinite DMRG algorithm can be adapted to find the
degenerate ground states of a microscopic FQH Hamiltonian on an infinitely long
cylinder, then focus on two applications. To characterize the topological order
of the phase, I'll show that the bipartite entanglement spectrum of the groundCollection/Series:Scientific Areas:
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Tuesday Feb 05, 2013Speaker(s):
We have used a recently proposed quantum Monte Carlo
algorithm [1] to study spinons (emergent S = 1/2 excitations) in 2D
Resonating-Valence-Bond (RVB) spin liquids and in a J-Q model hosting a Neel –
Valence Bond Solid (VBS) phase transition at zero temperature [2]. We confirm
that spinons are well defined quasi-particles with finite intrinsic size in the
RVB spin liquid. The distance distribution between two spinons shows signatures
of deconfinement.Collection/Series:Scientific Areas:
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Friday Feb 01, 2013Speaker(s):
Two types of topological phases have attracted a lot of
attention in condensed matter physics:symmetry protected
Collection/Series:Scientific Areas:
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Thursday Jan 31, 2013Speaker(s):
In this talk I will present our recent investigations on
possible topological phases in (111) heterostructures of transition metal
oxide. These (111) heterstructures are promising systems to realize many 2D
topological phases at high temperatures, even with strong correlations, which
is hard to be achieved in conventional materials.Collection/Series:Scientific Areas:
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Tuesday Jan 22, 2013Speaker(s):
Using quantum Monte Carlo simulations, we investigate the
finite-temperature phase diagram of hard-core bosons (XY model) inCollection/Series:Scientific Areas:
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Tuesday Jan 08, 2013Speaker(s):
Recent experiments in BEC
quantum magnets exhibit a dramatic evolution ofCollection/Series:Scientific Areas:
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Friday Dec 14, 2012Speaker(s):(PDF)
Topological phases are quantum
phases that can not be described by any local order parameter.Collection/Series:Scientific Areas:
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Friday Nov 30, 2012Speaker(s):
We study the spectrum of the amplitude mode, the analog
of the Higgs mode in high energy physics, for the d-density wave (DDW) state
proposed to describe the anomalous phenomenology of the pseudogap phase of the
high Tc cuprates. Even though the state breaks translational symmetry by a
lattice spacing and is described by a particle-hole singlet order parameter at
the wave vector q = Q = (pi, pi), remarkably, we find that the amplitude mode
spectrum can have peaks at both q = (0, 0) and q = Q = (pi , pi). In general,Collection/Series:Scientific Areas:
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Friday Nov 30, 2012Speaker(s):
The search for Majorana zero-modes in condensed matter
system has attract increasing research interests recently. Looking for Majorna
zero-mode is actually looking for topologically protected ground state
degeneracy. The topological degeneracies on closed manifolds have been used to
discover/define topological order in many-body systems, which contain
excitations with fractional statistics. In this talk, I will present our recent
work on new types of topological degeneracy induced by condensing anyons alongCollection/Series:Scientific Areas:
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